The invention relates to a complementary push-pull class B final-stage having complementary driver transistors whose emitters are directly interconnected.
A transistor push-pull amplifier having a push-pull driver stage with two complementary transistors and a push-pull class B final-stage likewise containing two complementary transistors is known from DE-PS 25 54 770.
According to FIG. 2 of the above-mentioned publication, the complementary driver transistors whose emitters are directly interconnected are used to actuate this complementary push-pull class B final-stage. Since the DC voltage potential of these emitters is approximately half the operating voltage potential, the emitters can be connected to the link between the two collectors of the final-stage transistors. The connection of the two collectors of the final-stage transistors must have a DC voltage equal to half the operating voltage in order to achieve a high power output. To avoid amplification-reducing negative feedback, this connection is made via a filter section comprising one or two resistors and a capacitor.
This circuit array is not usable for integrated circuits since the capacitor of the filter section is not integratable on account of the high capacitance value (22 .mu.F in the cited reference). Therefore the switching point between the filter section resistor(s) and the emitters of the driver transistors would have to be designed as a connection point, entailing additional costs.